First, make sure you can make the shot without the pacer ball. Set the two ball combination with a ball on the spot and another one frozen to it so their centers are lined up towards the long rail half of the corner pocket. This should also set their tangent line up to the other corner. Find a cue ball position where you can consistently make the shot. I like it just under 1-1/2 diamonds from the long rail, just behind the headstring. I aim for a half ball hit on the first object ball in the combo with lots of left and a half tip of follow.

Once that part of the shot goes, you can try it with the pacer ball. From the cue ball position you need to hit the second part of the shot, freeze the pacer ball to it lined up with the corner pocket. Then back the cue ball off about a half diamond. Hit a slow stop shot so the cue ball doesn't move after sending the pacer on its way. Practice getting the speed so the pacer just gets to the corner.

The hard part of the shot is lining up and executing the second part of the shot up quickly enough so that the combo'd ball beats the pacer. No real tips here, it's just going to take practice.